The present invention relates to occupant detection. In particular, a sensor and circuit configuration is provided.
Occupant detection in conjunction with sensing a crash determines whether to activate an airbag. Various occupant detection systems have been proposed, including detection based on ultrasound, infrared, radar, electric field, capacitance, weight, optical, or combinations thereof. The occupant detection systems use antennas positioned in various locations within a vehicle, such as within a windshield, within a roof liner, in floor mats, or within a seat. The antennas are piezoelectric material, conductive materials, or other structures. For example, a conductive textile or flexible metallic electrode within a seat allows capacitive or electric field-based detection of an occupant. As another example, strain gauges or pressure sensing sensors on flexible circuit material within a base portion of the seat detect an occupant.
Typically, an array of antennas connects with an electronic control unit. The connections between the antennas and the electronic control unit may use releasable connectors, but compliant pins or other connectors may be used. The electronic control unit measures signals and determines the occupancy state of the seat or vehicle. The electronic control unit outputs the state information to an air bag controller. The air bag controller connects with the occupancy detection electronic control unit and a crash sensor. The air bag controller activates or does not activate the deployment of the air bag during a crash depending on the occupancy state.